JP4925213B2 - Medical pump - Google Patents

Description

  The present invention relates to a medical pump, and more particularly to a medical pump for water jet surgery.

  In the water injection operation, in the operation of the liver, this organ is completely different from other organs and has various rigid tissue structures (parenchyma, blood vessels and bile ducts), and the supplied injection water Has been used for some time because it detaches the tissue while leaving the blood vessels and bile ducts intact. Inevitably, precise control of the ablation pressure is required for this purpose.

  Yet another problem with water jet surgery is that the ablation medium must be completely sterilized (eg, by Ringer's solution) because the fluid is closest and most concentrated in contact with the body tissue. Common issues such as high reliability, simplicity and economic productivity must also be considered.

  Medical pumps for water jet surgery are known from each of the following US Patent Application No. 6,216,573B1 and German Patent Application No. 20309616U1, which are interchangeable So it is used only once. However, these requirements are not met for pump efficiency and its adjustment.

  The present invention can utilize medical pumps that facilitate improved ablation performance, especially medical pumps for water-jet surgery, despite the simple and appropriate configuration and hence single use It aims to make it.

  This problem is solved by a medical pump according to claim 1, in particular a medical pump for water jet surgery.

  The pump has at least two pistons with piston rods for moving the piston in the cylinder and for coupling to the pump actuator, a cylinder head for closing the cylinder relative to the piston, pressure And a valve device for connecting the chamber to at least one fluid outlet and at least one fluid inlet, thereby restricting the pressure at the fluid outlet to a predetermined maximum value. The part interacts with the fluid inlet via an adjustable pressure control valve.

  Since the pump is operated with two piston / cylinder units, an improved and particularly smooth pump capacity can be achieved. Economic productivity is guaranteed because of the simple construction. The already improved working fluid pumping can be improved by means of a pressure control valve, in particular it can be smoothed and at the same time adjusted to the respective application requirements.

  The valve device and / or pressure control valve is provided with a valve membrane that is elastic or elastically pressurized. This guarantees extremely economical productivity and high operational safety.

  The valve device also includes two spring-loaded backflow ball valves, which are also easy to make.

The pressure control valve is preferably configured as a force- driven valve in such a way that the maximum value can be adjusted by the operating force in the regulator of the pressure control valve. Such a special configuration facilitates the connection of the medical pump to the pump actuator in an advantageous manner, where no specific spatial positioning of the pump relative to the pump actuator is necessary. Since the pressure adjustment is not proportional to the stroke but proportional to the force, the connection of the pressure control valve to the adjustment unit is position-dependent (those that may require precise adjustment of the pump) Rather, it is an important, position-independent force by which the regulator activates the pressure control valve.

  The pressure control valve is disposed between the fluid inlet and the fluid outlet so that the fluid from the fluid outlet can be guided back to the fluid inlet when the maximum value is exceeded. Is preferred. In this way, the pressure can be adjusted independently of the amount of fluid pumped.

  These pistons or piston rods are preferably connected securely and sterilized to the cylinder via bellows, cup seals or similar non-slip seals. Thus, bacteria are not introduced despite the sterilized working fluid and sterilized transfer pipe, which may be the case with previously known pumps. This fear is due to piston movement in the cylinder, where the rear end of the piston in the cylinder is subjected to ambient air flow (relative to the pressure chamber) and thus the cylinder is contaminated with it in this area. Especially big.

  The valve device and / or pressure control valve is preferably housed in the cylinder head. This results in a simpler installation with fewer parts.

  The cylinder is preferably connected independently to the cylinder head. This simplifies manufacturing.

  The outlet is preferably provided with a fitting for irreversible connection to the pressure hose. This ensures that incorrect installation of the pump and further unacceptable reuse of the pump are avoided.

  The cylinder head is preferably provided with a holding device attached to the pump actuator, specifically a lug on which its fastener engages. Thus, no special means for attaching the pump to the pump actuator is necessary.

  In the preferred embodiment, an accumulator connected to the fluid outlet is envisaged, but this is configured in such a way that the fluid pressure fluctuations at the fluid outlet are smoothed by low passage effects. This provides a further smoothing of the ablation jet, thus making it desirable to improve the ablation function in the equipment. The accumulator is preferably located in the cylinder head or connected to it to simplify the assembly of the entire equipment.

  Preferred embodiments of the invention follow the description of the following examples, expressed in more detail by the dependent claims and the drawings.

  The same reference numerals are used for the same parts and parts with the same function.

  A pump actuator 10 is designed for the embodiment of the invention shown in FIG. 1, which includes a motor controller 15 for controlling two motors 11, 11 ′, The motors 11 and 11 ′ are connected to the piston rods 25 and 25 ′ via the gear devices 12 and 12 ′ and the clutch devices 13 and 13 ′. Since one operator B can actuate the motor controller 15 with a suitable switch (foot switch or finger switch), the motors 11, 11 ′ are connected to the piston rod 25 in the cylinders 21, 21 ′ of the pump unit 20. , 25 ′ and pistons 22, 22 ′ are moved alternately by the elements (components), whereby the volume of the pressure chambers 16, 16 ′ of the pump unit 20 is alternately increased and decreased.

  In order to seal the pressure chambers 16, 16 'and the pistons 22, 22' with respect to the cylinders 21, 21 ', seals 23, 23' are envisaged on the pistons 22, 22 '. Furthermore, the piston rods 25, 25 'maintain sterility with the cup seals 24, 24', but these cup seals 24, 24 'are on the one hand to the cylinders 21, 21' and on the other hand the piston rod 25. , 25 ', firmly fixed. In this way, when these cup seals 24, 24 'are not present, bacteria from the ambient air that adheres to the inner walls of the cylinders 21, 21' and pass through the seals 23, 23 'may mix with the working fluid. There is no risk of entering the working fluid.

  Suction valves 26 and 26 'and pressure valves 27 and 27' are connected to the pressure chambers 16 and 16 '. The suction valves 26, 26 ′ are connected via a fluid inlet 6 to a reservoir 9 for working fluid. The pressure valves 27 and 27 ′ are connected to the pressure resistant hose 5 through the fluid outlet 7, and the pressure resistant hose 5 is guided to the applicator 8. The pump unit 20 forms a disposable part E together with the storage tank 9 containing the contents, the pressure hose 5 and the applicator 8, which are discarded after each operation. It becomes possible to meet the requirements.

  In this simple embodiment of the present invention, the butterfly valve 14 (in addition to the motor controller 15) is designed for pressure regulation, and operator B facilitates fluid flow regulation.

The embodiment of the present invention shown in FIG. 2 differs from that shown in FIG. 1 due to the assumption of the pressure control valve 35, and the presence of the valve membrane 36 allows the fluid outlet 7 and The flow path for connection with the fluid inlet 6 can be opened and closed. Membrane 36 is actuated by actuator 30 via push rod 34 and spring 33 and dynamometer 31. The dynamometer 31 supplies the force proportional output signal to the control device 32 where the operator B can set the maximum pressure. Instead of a separate dynamometer 31, the operating current of the actuator 30, which is also force proportional, can also be measured.

This arrangement ensures that the fluid pressure can be accurately adjusted with the applicator 8. Furthermore, the pressure fluctuation caused by the piston operation is smoothed by the control valve 35. The important point is that, based on its configuration, the pressure control valve 35 is operated with a fluid pressurized membrane in a force-controlled manner and not in a stroke-controlled manner . Therefore, a pressure adjustment error does not occur even if there is a dimensional tolerance between the connection of the pump unit 20 to the pump actuator 10 . The reason is that it is not a geometric dimension (stroke), but the pressure control valve 35 is actuated by force .

The embodiment shown in FIG. 3 differs from the previously shown embodiment in that an accumulator 40 is assumed, which is sealed by a seal 43 and pressurized by a spring 41. It includes a cylinder 44 in which a piston 42 is housed. The chamber located above the piston is connected to the fluid outlet, so that when the pressure at the fluid outlet 7 increases, the spring 41 is compressed, and when the pressure decreases, the spring 41 causes the piston 42 to move. Driven. In this way, the pressure guided to the applicator 8 is smoothed by its low passing action. The accumulator 40 is arranged in a cylinder head 29 that seals the cylinders 21, 21 '.
Of course, it is possible to combine the modifications shown here. Specifically, the pressure control valve 35 can be combined with the accumulator 40.

  In FIG. 4, a structural embodiment of the pump device 20 is shown in an exploded view. In this embodiment, the pressure and suction valves 26/27 include balls 19 that are pressed onto the valve seat (not visible in the figure) via springs 18, which Basically known.

  The cylinder head 29 has two parts in which these valves are located between the cylinders 21, 21 ′ and the cylinder head 29 by connecting the cylinders 21, 21 ′.

  It can be further seen from FIG. 4 that the piston rods 25, 25 ′ have coupling projections 17, 17 ′ at their distal ends that act to create a mechanical connection with the coupling system 13, 13 ′. That is.

  The piston in this embodiment of the invention is formed by the proximal end of the piston rod 25, 25 'that fits with the cap 28 and simultaneously holds the seals 23, 23' securely to the piston rod 25, 25 '. .

  The pressure hose 5 is irreversibly fixed to the cylinder head 29 via an inner pipe inserted into the connecting piece 37, the crimping piece 38 and the pressure hose 5, so that the inside of the cylinder head 29 After the assembly of the connecting piece 37 at the fastener 45 in a known manner, the connecting piece is irreversibly held in the cylinder head 29.

  From FIG. 5 and FIG. 6, the details of the layout relate specifically to the structure of the suction valve 26, 26 ′ or the pressure valve 27, 27 ′, and in particular in the cylinder head 29, on the other hand It becomes clear with regard to the layout of the valve seat in the distribution cylinder 21, 21 '.

7 and 8 show cross-sectional views through the pressure control valve 35 so that the membrane 36 can be pressed onto the valve seat by the push rod 34 (FIG. 7 shows its open position). FIG. 8 shows its closed position), depending on the position of the membrane 36 between the fluid outlet part 7 and the fluid inlet part 6, but more or less than the larger “of the pump unit 20”. A “short circuit” is created. When the membrane 36 is pressurized by the fluid outlet 7, a force- controlled valve appears.

  FIG. 4 shows yet another structure related to the details of the cylinder head 29 and the valve devices (suction valve, pressure valve and pressure control valve) housed therein.

  Furthermore, FIG. 9 shows a lug (handle or knob shape) which is connected to the pump actuator 10 via the pump unit 20 or can be held securely there. .

  In an embodiment of the invention not shown here, not only is the pressure control valve 35 designed as a membrane valve, but two pressure valves 27, 27 'or suction valves 26, 26' are also shown here. Designed as a membrane valve instead of a ball valve. This makes the equipment more economical. Finally, it is also possible to make equipment such that not only all the valve membrane valves but also all the membranes are connected together, thereby further reducing the number of components.

1 is a schematic block diagram of an embodiment of a medical pump. 1 is a schematic block diagram of an embodiment of a medical pump. 1 is a schematic block diagram of an embodiment of a medical pump. An exploded view of an embodiment of this pump. FIG. 5 is a side view of the pump according to FIG. FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 3 is a partial cross-sectional view of a medical pump in a pressure control valve area at various control positions. FIG. 3 is a partial cross-sectional view of a medical pump in a pressure control valve area at various control positions. The perspective view of a cylinder head.

Explanation of symbols

E Disposable part
B operator
5 Pressure hose
6 Fluid inlet
7 Fluid outlet
8 Applicator
9 Reservoir
10 Pump actuator
11, 11 'motor
12, 12 'gearing
13, 13 'clutch system
14 Butterfly valve
15 Motor controller
16,16 'pressure chamber
17, 17 'Connecting projection
18 Spring
19 balls
20 Pump unit
21, 21 'cylinder
22, 22 'piston
23, 23 'seal
24, 24 'cup seal
25, 25 'piston rod
26, 26 'suction valve
27, 27 'pressure valve
28 cap
29 Cylinder head
30 Actuator
31 Dynamometer
32 Control unit
33 Spring
34 Push rod
35 Pressure control valve
36 Valve membrane
37 Connection piece
38 Crimping pipe
39 Inner pipe
40 Accumulator
41 Spring
42 piston
43 Seal
44 cylinders
45 Fastener
46

Claims (10)

At least two pistons with piston rods (25, 25 ') for moving the pistons (22, 22') in the cylinders (21, 21 ') and for coupling to the pump actuator (10) (22, 22 '),
A cylinder head (29) for sealing the cylinder (21, 21 ') and a pressure chamber (16, 16') in the cylinder (21, 21 ') with at least one fluid inlet (6) and at least one Valve devices (26, 26 ', 27, 27') for connection to two fluid outlets (7),
In order to limit the pressure at the fluid outlet (7) to a predetermined maximum value, an adjustable pressure control valve (35) is provided,
The pressure control valve (35) is actuated by an actuator (30) via a push rod (34) and a spring (33) and a dynamometer (31) ,
The dynamometer (31) measures a force acting on the spring (33) and supplies a force proportional output signal to a control device (32) for controlling the operation of the actuator (30). A medical pump for water-jet surgery characterized in that B) can set the maximum pressure via the control device (32) .   The pressure control valve (35) pipes the fluid from the fluid outlet (7) back to the fluid inlet (6) when the maximum value is exceeded, so that the fluid inlet (6) and the fluid outlet It is connected to (7), The medical pump of Claim 1 characterized by the above-mentioned.   3. The valve device (26, 27) and / or the pressure control valve (35) is provided with a valve membrane (36) that is elastic or elastically pressurized. Medical pumps. The medical pump according to claim 1 or 2 , characterized in that the valve device (26, 27) comprises a spring-biased backflow ball valve. The pressure control valve (35) is force controlled in such a way that the maximum value can be adjusted by the moving force of the push rod (34) acting on the valve membrane (36) of the pressure control valve (35). The medical pump according to claim 3 or 4, wherein the medical pump is configured as a valve.   The piston (22, 22 ') or piston rod (25, 25') maintains sterility to the cylinder (21, 21 ') via a bellows, cup seal or similar non-slip seal (24, 24'). The medical pump according to any one of claims 1 to 5, wherein the medical pump is connected in a sealed manner.   The valve device (26, 27) and / or the pressure control valve (35) is at least partly fitted in the cylinder head (29). Medical pump according to one.   The medical pump according to any one of claims 1 to 7, characterized in that the cylinders (21, 21 ') are individually connected to the cylinder head (29).   The fluid outlet (7) has a connection device (37-39, 45) for connection with a pressure-resistant hose (5). A medical pump according to 1.   The cylinder head (29) is characterized by having a holding device attached to the pump actuator (10), in particular a lug (46) for engagement of a holding fastener. The medical pump according to any one of claims 1 to 9.

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